Does pegvisomant treatment expertise improve control of resistant acromegaly? The Italian ACROSTUDY experience.

Abstract

GH receptor antagonist pegvisomant is indicated for treatment of patients with resistant acromegaly. We compared safety and treatment outcomes of pegvisomant therapy in patients managed by Italian centers enrolling less or more than 15 cases in ACROSTUDY, a safety surveillance study of long-term pegvisomant treatment of patients with acromegaly. A noninterventional safety surveillance study in which safety and treatment outcomes of pegvisomant were evaluated on the basis of data collected during a 7-year period. A total of 204 acromegaly patients treated by seven centers enrolling 16-49 patients each (group A) and 137 subjects by 18 centers following 3-14 cases ( group B). Patients of group A and B were treated for 4.4±2.7 and 4.2±2.2years, respectively. IGF-1 ULN normalized in 64.4% (n=56) and 54.4% (n=31) in group A and B, respectively, after 1-year treatment, and in 57.3% (n=106) and 72.5% (n=87) at last visit. Starting doses were significantly higher in group A. They were progressively increased during treatment in both groups, but were higher in uncontrolled patients than in controlled ones only in group A. Reported adverse events were more frequent, and the prevalence of patients with adverse events was higher in group B. On the basis of this original study approach, we could speculate that in the centers in which more patients are treated with pegvisomant, less adverse events are reported, but the long-term effectiveness is lower than in centers with less cases, perhaps because of an inadequate patient's selection.